html,
body {
  width: 100%;
  height: 100%;
}
body {
  padding-top: 45px;
}
.header_item {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 45px;
}
.active {
  display: none;
}
.item_conter {
  width: 100%;
}
.item_conter .conter1 {
  width: 100%;
}
.item_conter .conter1 li {
  width: 45%;
  float: left;
  margin: 10px;
  box-sizing: border-box;
}
